In the printing industry, there are generally two types of inks, dispersion inks and solution inks. Dispersion inks have been widely used throughout the years because they more easily can be formulated. The primary disadvantage of dispersion inks is that their components tend to settle and, as a result, the inks must be agitated on occasion. Although solution inks do not have a settling problem, they are more difficult to produce. Recently, strides have been made in the capability of producing solution inks, but such inks have been found to be incompatible with contemporary systems that are used to apply inks. For example, in the printhead of a postage meter, an inking pad, or roller, hereafter collectively referred to as inking member, will contact the printhead to transfer ink thereto and the inking member will be removed from the printhead so that the inked print head can contact a mailpiece to print an indicia.
In developing solution inks, it has been found that inking members that are acceptable for use with dispersion inks simply are not efficient when used with solution inks. This is because inking members suitable for dispersion inks have pores that are too large. Such large pore sizes are required to allow dispersed particles to be distributed through the inking member. Additionally, typical inking members for dispersion inks were found to be incompatible with polyglycols, a component of contemporary solution inks. Consequently, it has become evident that if the benefits offered by solution inks are to be realized, inking members must be developed that will enhance the use of such inks.
In copending applications Rechargeable Inking Pad and Method of Producing a Felted Polychloroprene Foam and Method of Shaping and Felting Polychloroprene Latex Foam, a method is disclosed wherein foam made of polychloroprene can be felted. This had heretofore been considered an unobtainable goal because of the resiliency and lack of compression set of polychloroprene. Although the method proved satisfactory, it became evident that a reduced felting time and greater tolerance of incoming lot variations would be desirable.